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ACTION-333 Quick Review of Quick Reference Guide

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Wed, 22 Apr 2009 19:08:24 -0400 (EDT)
Message-Id: <20090422.190824.15807011.pfps@research.bell-labs.com>
To: public-owl-wg@w3.org

	Quick Review of QRG

I reviewed the version of 22 April 2009.  This version has the link
column up to about Section 2.2.1.

General comments:

- Satisfying the following comments will require quite large changes to
  the document.  A re-review will be needed.

- Moving the links to a separate column is a bad idea.  It consumes
  extra space to no good effect.  Links in the QRG should be from the
  relevant information itself, as they used to be.

- Links to NF&R are not very useful in the QRG.  Users of this document
  will not be interested in why a new feature had been added to OWL 2.
  Instead they will be interested in what the feature is (and thus the
  old links from the FS column are useful) and in how to use the feature
  (and thus the links to the Primer are useful).  I suggest that all
  links to NF&R be removed.  

- Links to the RDF Mapping do not provide any useful information and
  should also be used.  This document itself provides the information
  needed about the mapping, and in a form much more likely to be
  comprehensible by the readers of this document.

- The document is missing named classes, properties, and individuals.
  Lines like the following should be added:
  Named class  U  U
  In some places names are required but the document does not
  distinguish between names and expressions.  The places that I noticed
  where names are required are 2.6 Declarations and 2.7 Annotations.

- This document should use terminology from the normative OWL 2
  documents.  This requires at least some changes to the following
  OWL class -> class expression 
  object property -> object property expression
  I second Christine's comment to use the same short forms as in SS&FS,
  in general, but it may be that C is better than CE, if only to save

  I suggest the following start of a fix for the notation paragraph:

    We use the following notation conventions: "C" is a class
    expression, "D" is a data range, "P" is an object property
    expression, "R" is a data property, "A" is an annotation property,
    "a" is an OWL individual, "v" is a literal, and "n" is a
    non-negative integer. All of the previous can have subscripts.
    "_:x" is a blank node.  "(a1 ... an)" is an RDF list.

  Then use subscripts where Q, S, and v were used before.

- There are some awkward sentences in the document.  I haven't changed
  them, but a final pass should be made after the content is fixed.

- Subsections should be used sparingly.  I suggest no sub-sub-sections
  (2.1.1, etc.) at all.

- This document does not really need to address n-ary data ranges.  I
  suggest removing all mention of n-ary data ranges and their support.

- In some places the document uses explicit iteration (n-ary individual
  equality) and in some places it uses implicit iteration (equivalent
  properties).  Only one should be used.  I suggest implicit.

- The document is missing some constructs.  I noticed:
  - prefixes
  - datatype definitions
  - names, literals
  - individuals - named and anonymous

- It would probably be better to merge all the datatype and data range
  stuff into one section.  The built-in datatypes could be more
  succinctly presented by just listing the xsd datatypes.

Specific comments:

- The abstract needs to be completely rewritten, to be something like:

  This document provides a quick reference guide to the OWL 2 language.

- Section 1 should be renamed to "Prefixes" and the first sentence
  changed to "The standard prefixes in OWL 2 are:" to conform with the
  wording in the normative OWL 2 documents.

- "_:x" is a blank node. All of these can have subscripts.

- The link for RDF lists should probably point to Turtle or some other
  place that uses this syntax for RDF lists.

- "all OWL individuals" -> "universal class" (maybe)

- The "Every owl:Restriction is an owl:Class." sentence is not needed at

- The presentation of cardinalities should be made easier to understand.
  I suggest something like

 		    |		                   | _:x rdf:type owl:Restriction.
 		    | ObjectExactCardinalty(n P)   | _:x owl:onProperty P.
 		    | 			           | _:x owl:cardinality n.
  exact cardinality | -----------------------------|------------------------
  		    |			           | _:x rdf:type owl:Restriction.
 		    | ObjectExactCardinalty(n P C) | _:x owl:onProperty P.
 		    | 			      	   | _:x owl:qualifiedCardinality n.
 		    | 				   | _:x owl:onClass C.

- "<x> Properties are instances of owl:<x>Property" should be changed to
  just "<x> Property Expressions".  The last bit is not part of the FS,
  and in any case doesn't add any information.

- "universal <x> property" and "empty <x> property"

- The range of a datatype property axiom is a data range, not a class.

- Data range intersection and union are switched up in the table.

- positive object property assertion needs to indicate that P is an
  object property, not an object property expression.

- A and AP are both used for annotation properties.  Only one should be.

- The section on Annotations needs work.  Object annotations are on
  names only, for example.  The full fixing up of this section should be
  done after some of the above changes are made.

- The FS for deprecation doesn't need the short form - just write out.
  Deprecation can be used for individuals as well.

- The section on ontologies should not say "Annotations of Ontologies".  

- This is a quick reference guide and does not need to mention all the
  arcana.  Therefore the section on deprecation should be deprecated.


- I fixed a few typos.  If the document is reverted these may need to be
  Abstract: his -> This
  2: an rdf list. 
  2.1: _:x  owl:hasValue a.
       an n-ary data range
  2.2.1: bottom  object property
  2.5: a rdf:type C
Received on Wednesday, 22 April 2009 23:08:38 UTC

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